异步联网后南方电网区域间失步振荡特性及应对措施

Out-of-step Oscillation Characteristics and Countermeasures After Asynchronous Interconnection in China Southern Power Grid

为研究异步联网后主网失步振荡特性,利用两侧相位差定位振荡中心及U cosφ原理判别失步解列装置动作的方法,对异步联网后典型方式下的多重严重故障进行仿真研究,总结出区域间断面呈现出振荡中心迁移、两广断面选择性、断面部分通道解列不开及断面协调性等特性,将导致就地失步解列装置不能完全解列断面或多断面同时解列。为此,提出基于就地解列装置,利用远方通信构建的广域失步解列控制系统。该系统融合就地量测与全局信息,实现集中决策与分散控制,能够有效避免断面不能完全解列及多断面同时解列。同时研究了低压减载、解列的时刻及解列点的选择对电网振荡特性和解列后电网恢复的影响,用于指导广域失步解列控制系统的控制策略制订。

To study the out-of-step oscillation characteristics after asynchronous interconnection,this paper makes a simulation of multiple severe faults in the typical mode by using the phase angle difference between the two sides to locate the oscillation center and U cosφprinciple to determine the action of the out-of-step splitting device.It is concluded that the inter-section in the China southern power grid presents characteristics,such as oscillation center migration,the selectivity of the Guangdong-Guangxi channels,no-splitting of some channels in section leading to the problem that local out-of step splitting device cannot completely split sections or split multiple cross-sections simultaneously.Therefore,the paper proposes to use the wide-area splitting control system using remote communication based on the local splitting device.The system integrates local measurement and global information to achieve centralized decision and decentralized control,which can effectively avoid incomplete splitting and the simultaneous splitting of multiple sections.Meanwhile,it studies the effects of under voltage load shedding,power commissioning,the selection of the time and the situation to trip on the grid oscillation characteristics and grid recovery after splitting to guide formulation of the control strategy for the wide-area out-of splitting control system.